CVE-2025-61772 (High) detected in rack-3.1.16.gem

[mend-bolt-for-github]

CVE-2025-61772 - High Severity Vulnerability

Vulnerable Library - rack-3.1.16.gem

Rack provides a minimal, modular and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and software in between (the so-called middleware) into a single method call.

Library home page: https://rubygems.org/gems/rack-3.1.16.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /vendor/cache/rack-3.1.16.gem

Dependency Hierarchy:

• manageiq-style-1.3.3.gem (Root Library)
  • rubocop-rails-2.32.0.gem
    • ❌ rack-3.1.16.gem (Vulnerable Library)

Found in base branch: master

Vulnerability Details

Rack is a modular Ruby web server interface. In versions prior to 2.2.19, 3.1.17, and 3.2.2, "Rack::Multipart::Parser" can accumulate unbounded data when a multipart part’s header block never terminates with the required blank line ("CRLFCRLF"). The parser keeps appending incoming bytes to memory without a size cap, allowing a remote attacker to exhaust memory and cause a denial of service (DoS). Attackers can send incomplete multipart headers to trigger high memory use, leading to process termination (OOM) or severe slowdown. The effect scales with request size limits and concurrency. All applications handling multipart uploads may be affected. Versions 2.2.19, 3.1.17, and 3.2.2 cap per-part header size (e.g., 64 KiB). As a workaround, restrict maximum request sizes at the proxy or web server layer (e.g., Nginx "client_max_body_size").

Publish Date: 2025-10-07

URL: CVE-2025-61772

CVSS 3 Score Details (7.5)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2025-10-07

Fix Resolution: https://github.com/rack/rack.git - v3.2.2

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